Add callbacks to MIDI actions

alsa.c

 #include <glib.h>
 
-#include "panelcontrol.h"
 #include "alsa.h"
 
+struct button_map_entry {
+	enum button button;
+	button_callback_fn callback;
+	void *userdata;
+};
+
+struct encoder_map_entry {
+	enum encoder encoder;
+	encoder_callback_fn callback;
+	void *userdata;
+};
+
+struct button_callbacks {
+	size_t len;
+	struct button_map_entry *items;
+} button_callbacks = {0};
+
+struct encoder_callbacks {
+	size_t len;
+	struct encoder_map_entry *items;
+} encoder_callbacks = {0};
+
+void button_callback_add(enum button button, button_callback_fn cb, void *userdata) {
+	button_callbacks.len++;
+	button_callbacks.items = realloc(button_callbacks.items,
+			sizeof(struct button_map_entry) * button_callbacks.len);
+	struct button_map_entry *entry = &button_callbacks.items[button_callbacks.len - 1];
+	entry->button = button;
+	entry->callback = cb;
+	entry->userdata = userdata;
+}
+
+void encoder_callback_add(enum encoder encoder, encoder_callback_fn cb, void *userdata) {
+	encoder_callbacks.len++;
+	encoder_callbacks.items = realloc(encoder_callbacks.items,
+			sizeof(struct encoder_map_entry) * encoder_callbacks.len);
+	struct encoder_map_entry *entry = &encoder_callbacks.items[encoder_callbacks.len - 1];
+	entry->encoder = encoder;
+	entry->callback = cb;
+	entry->userdata = userdata;
+}
+
+
+void midi_button_led(snd_seq_t *seq, int port, enum button button, enum button_led_state state) {
+	snd_seq_event_t ev;
+	snd_seq_ev_clear(&ev);
+	snd_seq_ev_set_source(&ev, port);
+	snd_seq_ev_set_subs(&ev);
+	snd_seq_ev_set_direct(&ev);
+	snd_seq_ev_set_noteon(&ev, 0, button, state);
+	snd_seq_event_output_direct(seq, &ev);
+}
+
 static gboolean on_alsa_readable(GIOChannel *source, GIOCondition condition, gpointer data) {
 	fprintf(stdout, "source=%p cond=%i data=%p\n", (void *)source, condition, data);
 	snd_seq_t *seq = (snd_seq_t *)data;
@@ -19,12 +71,21 @@ static gboolean on_alsa_readable(GIOChannel *source, GIOCondition condition, gpo
 		switch (ev->type) {
 			case SND_SEQ_EVENT_NOTEON:
 				fprintf(stdout, "button %i: %i\n", ev->data.note.note, ev->data.note.velocity > 0);
-				snd_seq_ev_set_subs(ev);
-				snd_seq_ev_set_direct(ev);
-				snd_seq_event_output_direct(seq, ev);
+				for (size_t i = 0; i < button_callbacks.len; i++) {
+					struct button_map_entry *entry = &button_callbacks.items[i];
+					if (entry->button == ev->data.note.note) {
+						entry->callback(ev->data.note.note, ev->data.note.velocity, entry->userdata);
+					}
+				}
 				break;
 			case SND_SEQ_EVENT_CONTROLLER:
 				fprintf(stdout, "knob %i: %i\n", ev->data.control.param, ev->data.control.value);
+				for (size_t i = 0; i < encoder_callbacks.len; i++) {
+					struct encoder_map_entry *entry = &encoder_callbacks.items[i];
+					if (entry->encoder == ev->data.control.param) {
+						entry->callback(ev->data.control.param, ev->data.control.value, entry->userdata);
+					}
+				}
 				break;
 		}
 		snd_seq_free_event(ev);
@@ -33,8 +94,6 @@ static gboolean on_alsa_readable(GIOChannel *source, GIOCondition condition, gpo
 	return TRUE;
 }
 
-static int port;
-
 void alsa(int source, snd_seq_t **seq_ret, int *port_ret) {
 	// connect to ALSA seq
 	snd_seq_t *seq;

alsa.h

 #include <alsa/asoundlib.h>
 
+#include "panelcontrol.h"
+
+typedef void (*button_callback_fn)(enum button button, enum button_direction direction, void *userdata);
+typedef void (*encoder_callback_fn)(enum encoder encoder, int delta, void *userdata);
+
+void button_callback_add(enum button button, button_callback_fn cb, void *userdata);
+void encoder_callback_add(enum encoder encoder, encoder_callback_fn cb, void *userdata);
+
+void midi_button_led(snd_seq_t *seq, int port, enum button button, enum button_led_state state);
+
 void alsa(int source, snd_seq_t **seq_ret, int *port_ret);

pa.c

@@ -77,9 +77,11 @@ static void xpa_on_connect(pa_context *ctx, void *userdata) {
 		// subscribe to PA sink input changes (volume, output, mute, new source)
 		pa_context_set_subscribe_callback(ctx, &xpa_on_subscribe, NULL);
 		pa_operation_unref(pa_context_subscribe(ctx, PA_SUBSCRIPTION_MASK_SINK | PA_SUBSCRIPTION_MASK_SINK_INPUT, NULL, NULL));
-		// initialize watched sink inputs by listing all
-		pa_operation_unref(pa_context_get_sink_input_info_list(ctx, &xpa_on_sink_input_info, &sink_inputs));
+		// initialize watched sinks/etc by listing all
+		// the order is important: sinks must be known before
+		// sink inputs so latter can access former in callbacks
 		pa_operation_unref(pa_context_get_sink_info_list(ctx, &xpa_on_sink_info, &sinks));
+		pa_operation_unref(pa_context_get_sink_input_info_list(ctx, &xpa_on_sink_input_info, &sink_inputs));
 	}
 }
 

panelcontrol.c

@@ -8,53 +8,11 @@
 #include "pa.h"
 #include "pa_siso_watch_list.h"
 
-
-//void toggle_mute(enum button button, void *userdata) {
-//	const char *name = (const char *)userdata;
-//	//xpa_sink_inputs_apply_by_name(name, &xpa_sink_input_set_volume, volume);
-//}
-//
-//typedef void (*button_action_fn)(enum button, void *);
-//
-//struct button_map_entry {
-//	enum button button;
-//	button_action_fn action;
-//	void *userdata;
-//};
-//
-//static const struct button_map_entry button_map[] = {
-//	{.button = TOP1, .sink_input = NULL, .action = &toggle_mute, .userdata = "mpd pulse"},
-//};
-//
-//
-//typedef void (*encoder_action_fn)(enum button, void *);
-//
-//struct encoder_map_entry {
-//	enum encoder encoder;
-//	encoder_action_fn action;
-//	void *userdata;
-//}
-//
-//static const struct encoder_map_entry encoder_map[] = {
-//	{.encoder = ENC1, .sink_input = NULL, .action = &change_volume},
-//};
-
-
 struct seq_port {
 	snd_seq_t *seq;
 	int port;
 };
 
-void midi_button_led(snd_seq_t *seq, int port, enum button button, enum button_led_state state) {
-	snd_seq_event_t ev;
-	snd_seq_ev_clear(&ev);
-	snd_seq_ev_set_source(&ev, port);
-	snd_seq_ev_set_subs(&ev);
-	snd_seq_ev_set_direct(&ev);
-	snd_seq_ev_set_noteon(&ev, 0, button, state);
-	snd_seq_event_output_direct(seq, &ev);
-}
-
 void show_mute_and_speakers(struct siso_watch *w) {
 	struct seq_port *sp = w->userdata;
 	midi_button_led(sp->seq, sp->port, TOP1, w->mute ? BUTTON_LED_ON : BUTTON_LED_OFF);
@@ -64,6 +22,14 @@ void show_mute_and_speakers(struct siso_watch *w) {
 	midi_button_led(sp->seq, sp->port, BOTTOM1, w->target == speakers ? BUTTON_LED_ON : BUTTON_LED_OFF);
 }
 
+void button_test(enum button button, enum button_direction direction, void *userdata) {
+	fprintf(stdout, "button pressed: %i dir=%i\n", button, direction);
+}
+
+void encoder_test(enum encoder encoder, int delta, void *userdata) {
+	fprintf(stdout, "encoder turned: %i delta=%i\n", encoder, delta);
+}
+
 int main(int argc, char *argv[]) {
 	if (argc != 2) {
 		fprintf(stderr, "usage: %s CLIENT_ID\n", argv[0]);
@@ -71,6 +37,9 @@ int main(int argc, char *argv[]) {
 	}
 	int source = atoi(argv[1]);
 
+	// keep track of speakers sink PA index
+	siso_add_name(&sinks, "speakers");
+
 	struct seq_port sp;
 	alsa(source, &sp.seq, &sp.port);
 
@@ -78,8 +47,9 @@ int main(int argc, char *argv[]) {
 	mpd->userdata = &sp;
 	mpd->volume_changed = show_mute_and_speakers;
 
-	// keep track of speakers sink PA index
-	siso_add_name(&sinks, "speakers");
+
+	button_callback_add(TOP1, button_test, NULL);
+	encoder_callback_add(ENC1, encoder_test, NULL);
 
 	pa();
 

panelcontrol.h

@@ -29,6 +29,11 @@ enum button_led_state {
 	BUTTON_LED_OFF = 0,
 };
 
+enum button_direction {
+	BUTTON_DOWN = 127,
+	BUTTON_UP = 0,
+};
+
 enum encoder {
 	ENC1 = 16,
 	ENC2 = 17,